Transcript The Nature of Zoology

An introduction to the concepts that make
zoology what it is.
Do you remember the Seven
Characteristics of Living Things
that you learned in Biology?
Forget about them!
We are not in Kansas anymore , Toto!
I. Fundamental
Properties of Life
1. Chemical Uniqueness
Living systems exhibit a
unique and complex
molecular structure
No matter how much we are
alike, we are so very much
different from one another.
2. Complexity and
Hierarchical Organization
Atoms
Molecules
Cells
Organs
Systems
Organisms
Communities
Ecosystems
Biosphere
Tissues
Populations
Biomes
In the Biological Hierarchy,
there are certain
properties that emerge at
a given level of the
hierarchy, which we call
emergent properties.
3. Reproduction
Do you remember “All living things
reproduce”?
Now, ask yourself , “How?”
Is everything the same?
Reproduction
Heredity
You are what your parents are!
Variation
Fortunately, there are other sources
and you can get a wide variety of
traits from all of the previous
generations!
4. Possession of a Genetic Code
DNA and the sequencing of
the nucleic acids that make
it up create a genetic code.
This controls the framework
by which all life is/was
created! SAME proteins –
different sequences!
5. Metabolism
All of the chemical activities of
the body make up the
METABOLISM of an organism.
6. Development
•This involves CHANGE,
not GROWTH
•Significant change AFTER
EMBRYONIC DEVELOPMENT
results in what we call
METAMORPHOSIS
7. Environmental Interaction
•The study of how organisms
interact with their environment
is called ECOLOGY.
Let’s have some fun!
II. Life Obeys Physical Laws
A. The First Law of Thermodynamics
(The Law of Conservation of Energy)
B. The Second Law of Thermodynamics
(Also known as the Law of Entropy)
III. Zoology as a Part of Biology
A. Zoology is the study of animals.
So……
what is an animal?
Animals are:
Mobile
Eukaryotic
Multicellular
Heterotrophs
IV. Principles of Science
A. Arkansas tries to initiate teaching of
Creationism rather than Evolution.
B. ACLU files suit
C. Arkansas decides to teach both
D. ACLU files suit again
Principles of Science (cont.)
1982 – Judge William Overton
1. Science is guided by natural law
2. Science is explanatory by reference to
natural law
3. Science is testable against the
observable world
4. Science is tentative, its results are
never final!
5. Science is falsifiable
V. Scientific Method: A new name !
Hypothetico-deductive method
Control – The part of an experiment where NOTHING
changes, to have a group to reference against.
Independent Variable – What is being tested
Dependent Variable – anything that happens as a result of the
Independent Variable.
•Powerful theories that guide extensive research are called
PARADIGMS.
VI. Experimental Science vs.
Evolutionary Science
Experimental
Evolutionary
Answers proximal causes
Answers ultimate causes
How things work NOW
How things CAME TO BE
VII. Charles Darwin and Evolution:
The truths, the half-truths, and
the myths.
Voyage of the H.M.S. Beagle
1831 -1835
Galapagos
Islands
Sir Charles Darwin in later years
Most people do not
realize several
aspects of his life.
Like most other
scientists of his time,
he was a priest.
•Tenets of Darwinian Theory:
•Perpetual Change
•Gradualism
•Natural Selection
•Multiplication of Species
•Common Descent
1. Perpetual Change
Nothing on the Earth stays the same,
but is constantly changing in a
noncyclical fashion
The
volcanic
Island of
Surtsey,
Formed in
1963
2. Gradualism
Height in feet
The tenet that large anatomical differences in species
occurred in small increments over long periods of time.
(Since disputed)
9
8
7
6
5
4
3
2
1
0
Growth according to Gradualism
Height inTime
feet in
of Thousands
Giraffe Neckofaccording
to gradualism
years
Gradualism replaced:
Punctuated Equilibrium
NOT DARWINIAN !
Height in feet
Punctuated Equilibrium (according to Neo-Darwinism)
9
8
7
6
5
4
3
2
1
0
Time in Thousands of Years
3. Natural Selection
Survival of the fittest…..only the strong survive
Natural Selection:
•Animals produce more of their own kind than is necessary
in order to survive. (Salmon)
•There is a constant struggle for existence….food, water, etc.
•Organisms have variation, and those variations are
heritable for success or failure
•Organisms are constructed to meet the demands and
needs of their environment - ADAPTATION
4. Multiplication of Species
Isolated populations which no longer interbreed will
develop into different species as they become more
adapted to their specific habitat.
Multiplication of Species
Scrub Jay
Western
Scrub Jay
Island Scrub
Jay
Florida
Scrub Jay
5. Common Descent
This is really the only part of
evolutionary theory that gives anyone
any trouble – and the truth is,
evolution never said that man came
from monkeys! It says that man and
apes and monkeys all evolved from a
common ancestor.
Common Descent suggests:
•All forms of life evolved from a single organism in the ocean
•Those forms, through multiplication of species became
differentiated
•In 1955 Stanley Miller developed apparatus to show how
life could have begun
Ernst Haeckel’s
“Stammbaum des
Menschen”
or
“Pedigree of Man”
known today as the
phylogeny of man
At first, Darwin’s theory of
Evolution was not accepted by
science or the church, because of
the mistaken theory of blending
inheritance……
Then came another clergyman:
Gregor Mendel
The Austrian monk Gregor
Mendel (1822-1884) laid the
foundations for modern
genetics, although his work
was largely unknown until
long after his death.
Mendel developed the law of
independent assortment and the law of
particulate inheritance and disproved that
all offspring were a blend of their parents.
This slightly changed Darwin’s theory, but
made it work. The new theory of evolution,
based on Mendelian Genetics is known as
Neo-Darwinism.
VIII. Contributions to Cellular
Biology
What is the single most important scientific
contribution to the improvement of life in the 20th
century and beyond?
Clue #1: The man you see here
invented it!
Clue #2: He is Dutch.
Clue #3: He was the first to see
sperm.
Evolution of the Microscope
Anton van Leeuwenhoek
Charles A. Spencer
Robert Hooke
Animal Rights and Scientific Testing
Many people consider it cruel and inhuman to
test living animals by submitting them to
painful or deadly substances to check their
reactions. What is the controversy all about?
Congress passed a series of Amendments to
the Animal Welfare Act, which covers animal
care in laboratories and other facilities.
From those amendments, the following have come about:
•Reduction: reducing the number of animals needed for
experimentation
•Refinement: refining the techniques used in
experimentation to lower stress and suffering for tested
animals
•Replacement: replacing live animals with simulations or
cell cultures when possible
That’s All Folks!